Cytomegalovirus immediate-early 1 peptide–Major Histocompatibility Complex (CMV IE1-MHC)

The Cytomegalovirus immediate-early 1 (IE1) peptide–Major Histocompatibility Complex (MHC) is a molecular assembly found on the surface of cells infected with Human Cytomegalovirus (HCMV). The IE1 protein, encoded by the UL123 gene, is among the first viral products synthesized upon infection and is essential for initiating the viral transcription program and modulating host antiviral responses (UniProt P13202). Peptides derived from IE1, such as the immunodominant VLEETSVML epitope, are loaded onto MHC Class I molecules (typically HLA-A*02:01) and presented to the immune system (PubMed: 25609775). This complex serves as a primary signal for recognition by CD8+ cytotoxic T lymphocytes, which are crucial for controlling CMV latency and reactivation. In therapeutic contexts, these complexes are targeted by adoptive T-cell therapies and TCR-engineered cells to treat refractory CMV infections in hematopoietic stem cell or solid organ transplant recipients (PubMed: 31434705). Because IE1 is expressed very early in the viral life cycle, targeting these complexes allows for the elimination of infected cells before significant viral progeny are produced (PubMed: 29158373).

Other names

CMV IE1-HLA complexIE1 pMHCUL123 peptide-MHC complexCytomegalovirus IE1 antigen-presenting complex

T-cell receptor (TCR) mediated recognition leading to cytotoxic lysis of infected cells and induction of apoptosis.